Enhanced thermoelectric performance in p-type Mg3Sb2 via lithium doping

The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,the intrinsically p-type Mg3Sb2 shows low figure of merit（z T = 0.23 at 723 K） for its poor electrical conductivity.In this study,a series of Mg（3-x）LixSb2 bulk materials have been prepared by high-energy ball milling and spark plasma sintering（SPS） process.Electrical transport measurements on these materials revealed significant improvement on the power factor with respect to the undoped sample,which can be essentially attributed to the increased carrier concentration,leading to a maximum z T of0.59 at 723 K with the optimum doping level x = 0.01.Additionally,the engineering z T and energy conversion efficiency are calculated to be 0.235 and 4.89%,respectively.To our best knowledge,those are the highest values of all reported p-type Mg3Sb2-based compounds with single element doping.

Ammonia promotes the proliferation of bone marrow-derived mesenchymal stem cells by regulating the Akt/mTOR/S6k pathway

Ammonia plays an important role in cellular metabolism.However,ammonia is considered a toxic product.In bone marrow-derived mesenchymal stem cells,multipotent stem cells with high expression of glutamine synthetase(GS)in bone marrow,ammonia and glutamate can be converted to glutamine via glutamine synthetase activity to support the proliferation of MSCs.As a major nutritional amino acid for biosynthesis,glutamine can activate the Akt/mTOR/S6k pathway to stimulate cell proliferation.The activation of mTOR can promote cell entry into S phase,thereby enhancing DNA synthesis and cell proliferation.Our studies demonstrated that mesenchymal stem cells can convert the toxic waste product ammonia into nutritional glutamine via GS activity.Then,the Akt/mTOR/S6k pathway is activated to promote bone marrow-derived mesenchymal stem cell proliferation.These results suggest a new therapeutic strategy and potential target for the treatment of diseases involving hyperammonemia.

Exploration of Chinese Television Historical Comedy Drama Li Wei the Magistrate from the Perspective of Management

From the perspective of management,this paper sorted out the management thoughts of the Chinese Television Historical Comedy Drama Li Wei the Magistrate.Then,on the basis of the sorting,it analyzed and summarized the management ideas and actions of characters in the drama.Finally,it summarized the application of management measures in the management of organizations,including making clear management responsibilities,using limited resources to maximize benefits,being strict with relatives,and practicing forbearance all the time,to improve the overall efficiency and benefits of enterprises and organizations.

Colony-stimulating factor-1 receptor inhibition combined with paclitaxel exerts effective antitumor effects in the treatment of ovarian cancer

Ovarian cancer is the tumor with the highest mortality among gynecological malig-nancies.Studies have confirmed that paclitaxel chemoresistance is associated with increased infiltration of tumor-associated macrophages(TAMs)in the microenvironment.Colony-stimu-lating factor 1(CSF-1)receptor(CSF-1R)plays a key role in regulating the number and differ-entiation of macrophages in certain solid tumors.There are few reports on the effects of targeted inhibition of CSF-1R in combination with chemotherapy on ovarian cancer and the tu-mor microenvironment.Here,we explored the antitumor efficacy and possible mechanisms of the CSF-1R inhibitor pexidartinib(PLX3397)when combined with the first-line chemothera-peutic agent paclitaxel in the treatment of ovarian cancer.We found that CSF-1R is highly ex-pressed in ovarian cancer cells and correlates with poor prognosis.Treatment by PLX3397 in combination with paclitaxel significantly inhibited the growth of ovarian cancer both in vitro and in vivo.Blockade of CSF-1R altered the macrophage phenotype and reprogrammed the immunosuppressive cell population in the tumor microenvironment.

水稻叶色调控机制及相关基因研究进展

植物光合作用主要依赖绿色叶片,而叶片生长发育最直观的特征是叶色。目前已克隆200多个调控水稻(Oryza sativa)叶色的基因。水稻叶色调控机制复杂多样,涉及多条调控途径,包括光合色素的生物合成与降解、核-质信号转导和血红素的合成。此外,温度和光照强度等外部环境也会影响水稻叶色的变化。该文从分子机制、叶色相关基因及环境因素等方面总结了水稻叶色遗传调控机制,并提出该领域亟待解决的科学问题,以期为水稻高光效育种及应用提供理论支撑。

水稻茎秆细胞壁相关组分含量QTL定位及候选基因分析

水稻(Oryza sativa)倒伏是制约其生产的主要因素之一,而茎秆的机械强度影响水稻抗倒伏能力,且与茎秆细胞壁相关组分含量密切相关。通过调控水稻茎秆细胞壁相关组分含量提高水稻抗倒伏能力,是提高水稻产量与品质的有效途径。该研究用籼稻品种华占(O.sativa subsp.indica cv.‘HZ’)和粳稻品种热研2号(O.sativa subsp.japonica cv.‘Nekken2’)杂交获得F1代,经连续多代自交得到120个重组自交系(RILs)群体,并以此构建遗传连锁图谱。基于构建的高密度遗传图谱,对水稻茎秆细胞壁中纤维素、半纤维素和木质素含量相关QTLs进行定位,结果共检测到4个与纤维素含量相关的QTLs、12个与半纤维素含量相关的QTLs和8个与木质素含量相关的QTLs。对检测到的QTLs区间进行候选基因分析,共筛选到13个候选基因。利用q RT-PCR检测候选基因的表达水平,结果表明除LOC_Os02g58590和LOC_Os12g41720外,其余候选基因的表达量在双亲间均存在显著差异。研究结果为挖掘调控水稻茎秆机械强度的基因,进而筛选和培育抗倒伏能力强的水稻品种奠定了重要基础。

Spontaneous apoptosis of cells in therapeutic stem cell preparation exert immunomodulatory effects through release of phosphatidylserine

Mesenchymal stem cell(MSC)-mediated immunomodulation has been harnessed for the treatment of human diseases,but its underlying mechanism has not been fully understood.Dead cells,including apoptotic cells have immunomodulatory properties.It has been repeatedly reported that the proportion of nonviable MSCs in a MSC therapeutic preparation varied from 5-50%in the ongoing clinical trials.It is conceivable that the nonviable cells in a MSC therapeutic preparation may play a role in the therapeutic effects of MSCs.We found that the MSC therapeutic preparation in the present study had about 5%dead MSCs(DMSCs),characterized by apoptotic cells.Namely,1×10^(6) MSCs in the preparation contained about 5×10^(4) DMSCs.We found that the treatment with even 5×10^(4) DMSCs alone had the equal therapeutic effects as with 1×10^(6) MSCs.This protective effect of the dead MSCs alone was confirmed in four mouse models,including concanavalin A(ConA)-and carbon tetrachloride(CCI4)-induced acute liver injury,LPS-induced lung injury and spinal cord injury.We also found that the infused MSCs died by apoptosis in vivo.Furthermore,the therapeutic effect was attributed to the elevated level of phosphatidylserine(PS)upon the injection of MSCs or DMSCs.The direct administration of PS liposomes(PSLs)mimic apoptotic cell fragments also exerted the protective effects as MSCs and DMSCs.The Mer tyrosine kinase(MerTK)deficiency or the knockout of chemokine receptor C-C motif chemokine receptor 2(CCR2)reversed these protective effects of MSCs or DMSCs.These results revealed that DMSCs alone in the therapeutic stem cell preparation or the apoptotic cells induced in vivo may exert the same immunomodulatory property as the'living MSCs preparation"through releasing PS,which was further recognized by MerTK and participated in modulating immune cells.

1:250万月球岩石类型图

人类对月表物质成分的科学认识始于20世纪60~70年代.大量的无人和载人月球探测获得了珍贵的历史数据.利用这些数据资料,美国地质勘探局编制了最早的一批月球地质图,但由于当时缺乏全面的月表物质成分探测数据,早期的月表地质单元划分多以形貌特征为依据而缺少成分约束. 20世纪90年代以来,新一轮的月球探测任务获取了全月球表面的物质成分探测数据,为开展月表物质成分编图提供了第一手资料.通过对月表物质成分分布信息的研究,本研究建立了月球内动力地质作用形成的岩石类型分类体系.基于GIS平台编制完成的1:250万月球岩石类型分布图及建立的月球物质成分数据库,为开展月球数字地质图编研和月球地质综合研究以及未来其他天体的编图工作奠定了基础.

1:250万月球全月构造纲要图

月球构造演化受到以岩浆活动为主的内动力和以陨石撞击为主的外动力地质作用共同驱动.月球构造纲要图系统表达了月球构造和构造单元时空分布的信息,是当前月球构造和演化历史知识的综合.以嫦娥工程数据为基础,充分利用国际上其他月球探测数据和研究成果,建立了基于动力学机制的月球构造分类体系.根据月球构造的动力学成因机制,将其划分为外动力成因和内动力成因两大类,并结合形貌特征,进一步细分为线性构造和环形构造.综合地球物理、地球化学、地形和构造分布等特征,划分了月球的五大构造单元.通过制定月球构造纲要图编制的标准、流程、方法和图示图例,应用地理信息平台,完成了世界首幅1∶250万比例尺的月球全月构造纲要图.月球构造纲要图是科学研究、探测规划和着陆点选择的基础资料,同时也为其他天体构造图的编制提供了参考.

Correction: Spontaneous apoptosis of cells in therapeutic stemcell preparation exert immunomodulatory effects throughrelease of phosphatidylserine

After online publication of the article1,the authors noticed one inadvertent mistake in Fig.5a that needs to be corrected.In detail,the pathological picture of PBS group in Fig.5a is inadvertently duplicated as the image of PBS group in Fig.7b in the main text.This duplication is a result of errors in figure assembly,and the correct Fig.5 is provided as follows.The key findings of the article are not affected by these corrections.

Inactivated SARS-CoV-2 induces acute respiratory distress syndrome in human A CE2-transgenic mice

The development of animal models for COVID-19 is essential for basic research and drug/vaccine screening.Previously reported COVID-19 animal models need to be established under a high biosafety level condition for the utilization of live SARS-CoV-2,which greatly limits its application in routine research.Here,we gen erate a mouse model of COVID-19 un der a gen eral laboratory condition that captures multiple characteristics of SARS-CoV-2-induced acute respiratory distress syndrome(ARDS)observed in huma ns.Briefly,human ACE2-tra nsge nic(MCE2)mice were in tratracheally in stilled with the formaldehyde-inactivated SARS-CoV-2,resulting in a rapid weight loss and detrimental changes in lung structure and function.The pulmonary pathologic changes were characterized by diffuse alveolar damage with pulmonary consolidation,hemorrhage,necrotic debris,and hyaline membrane formation.The production of fatal cytokines(IL-β,TNF-α,and IL-6)and the infiltration of activated neutrophils,inflammatory monocyte-macrophages,and T cells in the lung were also determined,suggesting the activation of an adaptive immune response.Therapeutic strategies,such as dexamethasone or passive antibody therapy,could effectively ameliorate the disease progression in this model.Therefore,the established mouse model for SARS-CoV-2-induced ARDS in the current study may provide a robust tool for researchers in the standard open laboratory to investigate the pathological mechanisms or develop new therapeutic strategies for COVID-19 and ARDS.